It’s the first step in a process that includes the deployment of a 15 thousand strong UN force.
But just before the truce took effect Israeli warplanes struck a Hezbollah stronghold in eastern Lebanon and a Palestinian refugee camp killing one person.
The truce, follows a UN Security Council resolution calling for an end to hostilities, which was passed unanimously on Friday after weeks of diplomatic wrangling.
However, it is a fragile ceasefire with the Israeli army saying it will continue to maintain an air and sea blockade of Lebanon until there is a system to prevent weapons reaching Hezbollah guerrillas.
Israel has also said its troops would return fire if they came under attack.
Just hours after the ceasefire the first casualty – a Hezbollah fighter was killed in southern Lebanon in clashes with Israeli troops.
Meanwhile, the Lebanese government, although approving the ceasefire resolution, has postponed indefinitely a meeting on disarming Hezbollah.
Just hours before the ceasefire Israel launched an 11th hour bid to crush Hezbollah with waves of deadly air strikes while Shiite fighters unleashed a barrage of rockets.
More than 30 Lebanese civilians were killed as warplanes kept up their deadly bombing while five Israeli soldiers were also killed in action.
Mark Malloch Brown, the UN’s Deputy Secretary General, said it might take a month before a joint UN-Lebanese force was fully in place.
“It’s going to be weeks, not days and may even, before you hit the full total, be a month or so,” he told the BBC.
Israel meanwhile has urged the world to apply the UN resolution firmly, warning that Hezbollah must be dismantled and the Lebanese army quickly deployed in the south.
Israeli air strikes continued until minutes before the truce began.
In one of the deadliest raids over the weekend, at least 10 people were killed and 20 wounded by Israeli air strikes that hit eight buildings and a mosque in Beirut’s southern suburbs, emergency services said.
Israel’s army estimates it’s killed 530 Hezbollah guerrillas during one month of fighting in Lebanon and has released the names of 180 whose deaths it says have been verified.
However, Hezbollah has acknowledged only a few dozen dead during the conflict.
Peace activist’s son killed
Meanwhile the Israeli army said that Uri Grossman, the son of prominent Israeli author David Grossman, was among the 24 Israeli soldiers killed in combat on Saturday, just days after his father urged his government to reach a truce.
It was the highest single-day toll since the war began on July 12.
The UN resolution, unanimously adopted Friday by the Security Council, calls for a full cessation of hostilities and the deployment of a 15,000-strong international force in southern Lebanon.
Morocco, Indonesia, Italy, Turkey, Spain and Malaysia have already agreed to send troops to bolster the UN force there but Australia is still to make a decision on whether to take part.
The UN resolution also calls for the release of the two captive Israeli soldiers whose seizure on July 12 triggered the conflict, and for a solution to the issue of Lebanese prisoners held by Israel.
While approving the resolution, the Lebanese cabinet expressed reservations that it did not go far enough in condemning the large-scale Israeli destruction and that it failed to address the issue of the Israeli-occupied Shebaa farms.